557 citations · 5.2k across the 80 of their papers we have counts for
81 papers
Discrepancies between Chandrasekhar's theory of relaxation and -body simulations
Kerwann Tep, Douglas C. Heggie
Globular clusters are systems which are known to be particularly well described by two-body relaxation. In recent decades many studies have shown that Chandrasekhar's orbit-average…
Dynamics of star clusters with tangentially anisotropic velocity distribution
Václav Pavlík, Douglas C. Heggie, Anna Lisa Varri +1
Recent high-precision observations with HST and Gaia enabled new investigations of the internal kinematics of star clusters (SCs) and the dependence of kinematic properties on the…
Punctuated chaos and the unpredictability of the Galactic center S-star orbital evolution
Simon Portegies Zwart, Tjarda Boekholt, Douglas Heggie
We investigate the chaotic behavior of the S-star cluster in the Galactic center using precise -body calculations, free from round-off or discretization errors. Our findings rev…
Punctuated Chaos and Indeterminism in Self-gravitating Many-body Systems
Tjarda C. N. Boekholt, Simon F. Portegies Zwart, Douglas C. Heggie
Dynamical chaos is a fundamental manifestation of gravity in astrophysical, many-body systems. The spectrum of Lyapunov exponents quantifies the associated exponential response to…
The Effect of Stars on the Dark Matter Spike Around a Black Hole: A Tale of Two Treatments
Stuart L. Shapiro, Douglas C. Heggie
We revisit the role that gravitational scattering off stars plays in establishing the steady-state distribution of collisionless dark matter (DM) around a massive black hole (BH).…
The Kinematic Richness of Star Clusters - II. Stability of Spherical Anisotropic Models with Rotation
Philip G. Breen, Simon Rozier, Douglas C. Heggie +1
We study the bar instability in collisionless, rotating, anisotropic, stellar systems, using N-body simulations and also the matrix technique for calculation of modes with the pert…